Application of electro-fenton process for the treatment of methylene blue

The electrochemical removal of an aqueous solution containing 0.25 mM of methylene blue (MB), one of the most important thiazine dye, has been investigated by electro-Fenton process using a graphite-felt cathode to electrogenerate in situ hydrogen peroxide and regenerate ferrous ions as catalyst. The effect of operating conditions such as applied current, catalyst concentration, and initial dye content on MB degradation has been studied. MB removal and mineralization were monitored during the electrolysis by UV\u2013Vis analysis and TOC measurements. The experimental results showed that MB was completely removed by the reaction with \u2022OH radicals generated from electrochemically assisted Fenton\u2019s reaction, and in any conditions the decay kinetic always follows a pseudo-first-order reaction. The faster MB oxidation rate was obtained applying a current of 300 mA, with 0.3 mM Fe2+at T=35 \ub0C. In these conditions, 0.25 mM MB was completely removed in 45 min and the initial TOC was removed in 90 min of electrolysis, meaning the almost complete mineralization of the organic content of the treated solution

A Comprehensive Approach to Improve Performance and Stability of State-of-the- Art Air Electrodes for Intermediate Temperature Reversible Cells: An Impedance Spectroscopy Analysis

Solid oxide fuel cells (SOFC) are devices for the transformation of chemical energy in electrical energy. SOFC appear very promising for their very high efficiency, in addition to the capability to work in reverse mode, which makes them suitable for integration in production units powered with renewables. Research efforts are currently addressed to find chemically and structurally stable materials, in order to improve performance stability during long-term operation. In this work, we examine different approaches for improving stability of two state-of-the-art perovskite materials, La0.6Sr0.4Co0.2Fe0.8O3-\uf064 (LSCF) and Ba0.5Sr0.5Co0.8Fe0.2O3-\uf064 (BSCF), very promising as air electrodes. Two different systems are considered: (i) LSCF and BSCF porous electrodes impregnated by a nano-sized La0.8Sr0.2MnO3-\uf064 layer and (ii) LSCF-BSCF composites with the two phases in different volume proportions. The study considers the results obtained by electrochemical impedance spectroscopy investigation, observing the polarisation resistance (Rp) of each system to evaluate performance in typical SOFC operating conditions. Furthermore, the behaviour of polarisation resistance under the effect of a net current load (cathodic) circulating for hundreds of hours is examined, as parameter to evaluate long-term performance stability

Producción de plantines de petunia (Petunia híbrida) en sistema flotante

El sistema flotante es un tipo de producción hidropónica de plantines muy utilizado en el sector tabacalero argentino, pero en el sector florícola es nuevo y no está muy estudiado y difundido. Este sistema permite reducir la mano de obra y el uso de agua con respecto a otros sistemas de cultivo. Por otra parte, las plantas de petunia (Petunia hybrida) son muy cultivadas y requieren plantines de calidad. Por lo tanto, evaluar el sistema flotante con esta especie y lograr un plantín adecuado constituye un aporte valioso para el sector. El objetivo del presente trabajo fue producir plantines de petunia en sistema flotante como alternativa al sistema convencional. Se realizaron dos ensayos, en uno se comparó el sistema flotante frente al convencional con tres dosis de fertilizante (19-19-19): 71,5; 31,5; 59,4 mg L-1 de N-P-K, 143; 62,9; 118,7 mg L-1 de N-P-K y 286; 125,8; 237,4 mg L-1 de N-P-K, y en otro se compararon diferentes tipos y volúmenes de bandejas de siembra: 228 celdas de 10 cm3, 216 celdas de 15 cm3, 288 celdas de 10 cm3 y 288 celdas de 17cm3. Al finalizar ambos ensayos se midió por separado la masa seca de la parte aérea, radicular y total. Como resultado, se observó que los plantines obtenidos en el sistema flotante lograron mejor desarrollo que en el sistema convencional. Los plantines lograron un mayor desarrollo fertilizados con 143; 62,9; 118,7 mg L-1 ppm de N-P-K. El tamaño adecuado de bandeja fue de 228 celdas de 10 cm3. En este trabajo se logró obtener el manejo apropiado para producir plantines de petunia en sistema flotante.The floating system is a type of hydroponic seedling production system widely used in Argentina’s tobacco industry, but this system is new and it has not been very studied and disseminated in the flower industry. This system reduces the hand labor and the water used compared to other cropping systems. On the other hand, the plants of petunia (Petunia hybrida) are very cultivated and require of quality seedlings. Therefore, to evaluate the floating system with this species and to achieve adequate seedlings is a valuable contribution to the sector. The aim of this study was to produce seedlings of petunia in a floating system as an alternative to the conventional system. Two trials were conducted, one compared the floating system vs. the conventional with three doses of fertilizer (19-19-19): 71,5; 31,5; 59,4 mg L-1 of N-P-K, 143; 62,9; 118,7mg L-1 of N-P-K and 286; 125,8; 237,4 mg L-1 of N-P-K; and in the other were compared different types and volumes of seed trays: 228 cells of 10 cm3, 216 cells of 15 cm3, 288 cells of 10 cm3 y 288 cells of 17cm3. When both of these essays were finished, the dry mass of aerial part, root and total dry mass were separately measured. As a result, it was verobserved that the seedlings obtained in the floating system achieved better development than in the conventional system. The seedlings fertilized with 143; 62,9; 118,7 mg L-1 ppm of N-P-K achieved greater development. The appropriate size of the seed tray was 228 cells of 10 cm3. In this work was possible to obtain the proper management to produce petunia seedlings in floating system.Facultad de Ciencias Naturales y MuseoInstituto Nacional de Tecnología Agropecuari

Classification of argentine maize landraces in heterotic groups

26-33The genetic diversity of maize (Zea mays L) is a valuable and strategic natural resource that plays a key role in the breeding progress. However, exploitation of genetic variability from landraces has not reached a significant level of utilization in breeding programs in Argentina yet. In order to establish their breeding potential, the best 15 out of a group of about 300 landraces from Argentina, were evaluated for various agronomic characters in testcrosses with five lines representing different heterotic groups. Testcrosses were evaluated in nine environments during two growing seasons. A factorial array of those landraces and tester lines was used. Differences for landraces, testers, and landrace x tester interactions were detected for ear diameter and length, ear attachment and plant height, and grain yield. Yield data were further analyzed following additive main effects (landrace and tester) and multiplicative interaction (landrace x tester) models. The first two principal components were significant and accounted for 67 percent of that interaction. The first axis was consistent with the Argentine flint vs. US dent (Mo17), and US dent (B73) vs. US dent (Mo17) heterotic patterns. The second axis exhibited a contrast between Argentine flint and US dent (B73 or B73 derived line) heterotic groups. The first two principal components of the landrace x tester interaction and mean performance of testcrosses were considered to identify eight landraces as parents of three composite populations

Evaluation of Externality Costs in Life-Cycle Optimization of Municipal Solid Waste Management Systems

The development of sustainable solid waste management (SWM) systems requires consideration of both economic and environmental impacts. Societal life-cycle costing (S-LCC) provides a quantitative framework to estimate both economic and environmental impacts, by including “budget costs” and “externality costs”. Budget costs include market goods and services (economic impact), whereas externality costs include effects outside the economic system (e.g., environmental impact). This study demonstrates the applicability of S-LCC to SWM life-cycle optimization through a case study based on an average suburban U.S. county of 500 000 people generating 320 000 Mg of waste annually. Estimated externality costs are based on emissions of CO₂, CH₄, N₂O, PM_2.5, PM₁₀, NO_<i>x</i>, SO₂, VOC, CO, NH₃, Hg, Pb, Cd, Cr (VI), Ni, As, and dioxins. The results indicate that incorporating S-LCC into optimized SWM strategy development encourages the use of a mixed waste material recovery facility with residues going to incineration, and separated organics to anaerobic digestion. Results are sensitive to waste composition, energy mix and recycling rates. Most of the externality costs stem from SO₂, NO_<i>x</i>, PM_2.5, CH₄, fossil CO₂, and NH₃ emissions. S-LCC proved to be a valuable tool for policy analysis, but additional data on key externality costs such as organic compounds emissions to water would improve future analyses

Expectancies regarding the interaction between smoking and substance use in alcohol-dependent smokers in early recovery.

The purpose of this study was to investigate expectancies regarding the interaction between cigarette smoking and use of alcohol among alcohol-dependent smokers in early recovery, using the Nicotine and Other Substances Interaction Expectancies Questionnaire (NOSIE). Participants were 162 veterans, 97% male, with a mean age of 50 years, enrolled in a clinical trial aimed at determining the efficacy of an intensive smoking cessation intervention versus usual care. At baseline, participants were assessed on measures of smoking behavior, abstinence thoughts about alcohol and tobacco use, symptoms of depression, and smoking-substance use interaction expectancies. In addition, biologically verified abstinence from tobacco and alcohol was assessed at 26 weeks. Participants reported that they expected smoking to have less of an impact on substance use than substance use has on smoking (p &lt; .001). Severity of depressive symptoms was significantly associated with the expectancy that smoking provides a way of coping with the urge to use other substances (p &lt; .01). The expectation that smoking increases substance urges/use was predictive of prospectively measured and biologically verified abstinence from smoking at 26 weeks (p &lt; .03). The results add to our knowledge of smoking-substance use interaction expectancies among alcohol-dependent smokers in early recovery and will inform the development of more effective counseling interventions for concurrent alcohol and tobacco use disorders

El género Gomphocarpus (Apocynaceae: Asclepiadoideae) en la Argentina

Se reporta la presencia de dos especies del género Gomphocarpus (Apocynaceae, Asclepiadoideae) que crecen espontáneamente en la Argentina: G. fruticosus (escapada de cultivo) y G. physocarpus (naturalizada). Las mismas se describen, se indica su distribución geográfica, usos, polinización y dispersión. Además, se analiza el estatus de naturalización de estas especies en el país

Allocating the Burdens of Climate Action: Consumption-Based Carbon Accounting and the Polluter-Pays Principle

Action must be taken to combat climate change. Yet, how the costs of climate action should be allocated among states remains a question. One popular answer—the polluter-pays principle (PPP)—stipulates that those responsible for causing the problem should pay to address it. While intuitively plausible, the PPP has been subjected to withering criticism in recent years. It is timely, following the Paris Agreement, to develop a new version: one that does not focus on historical production-based emissions but rather allocates climate burdens in proportion to each state’s annual consumption-based emissions. This change in carbon accounting results in a fairer and more environmentally effective principle for distributing climate duties

The risk stratification of adverse neonatal outcomes in women with gestational diabetes (STRONG) study

Aims: To assess the risk of adverse neonatal outcomes in women with gestational diabetes (GDM) by identifying subgroups of women at higher risk to recognize the characteristics most associated with an excess of risk. Methods: Observational, retrospective, multicenter study involving consecutive women with GDM. To identify distinct and homogeneous subgroups of women at a higher risk, the RECursive Partitioning and AMalgamation (RECPAM) method was used. Overall, 2736 pregnancies complicated by GDM were analyzed. The main outcome measure was the occurrence of adverse neonatal outcomes in pregnancies complicated by GDM. Results: Among study participants (median age 36.8 years, pre-gestational BMI 24.8 kg/m2), six miscarriages, one neonatal death, but no maternal death was recorded. The occurrence of the cumulative adverse outcome (OR 2.48, 95% CI 1.59–3.87), large for gestational age (OR 3.99, 95% CI 2.40–6.63), fetal malformation (OR 2.66, 95% CI 1.00–7.18), and respiratory distress (OR 4.33, 95% CI 1.33–14.12) was associated with previous macrosomia. Large for gestational age was also associated with obesity (OR 1.46, 95% CI 1.00–2.15). Small for gestational age was associated with first trimester glucose levels (OR 1.96, 95% CI 1.04–3.69). Neonatal hypoglycemia was associated with overweight (OR 1.52, 95% CI 1.02–2.27) and obesity (OR 1.62, 95% CI 1.04–2.51). The RECPAM analysis identified high-risk subgroups mainly characterized by high pre-pregnancy BMI (OR 1.68, 95% CI 1.21–2.33 for obese; OR 1.38 95% CI 1.03–1.87 for overweight). Conclusions: A deep investigation on the factors associated with adverse neonatal outcomes requires a risk stratification. In particular, great attention must be paid to the prevention and treatment of obesity